package com.ygqh.baby.utils;

import java.security.MessageDigest;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * @Author: sunshuo
 * @Date: 2019/3/21 18:38
 * @Version: 1.0
 */
public class SHA1Util {

	private static final char[] HEX_DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

	/**
	 * Takes the raw bytes from the digest and formats them correct.
	 *
	 * @param bytes the raw bytes from the digest.
	 * @return the formatted bytes.
	 */
	private static String getFormattedText(byte[] bytes) {
		int len = bytes.length;
		StringBuilder buf = new StringBuilder(len * 2);
		// 把密文转换成十六进制的字符串形式
		for (byte aByte : bytes) {
			buf.append(HEX_DIGITS[(aByte >> 4) & 0x0f]);
			buf.append(HEX_DIGITS[aByte & 0x0f]);
		}
		return buf.toString();
	}

	public static String encode(String str) {
		if (str == null) {
			return null;
		}
		try {
			MessageDigest messageDigest = MessageDigest.getInstance("SHA1");
			messageDigest.update(str.getBytes());
			return getFormattedText(messageDigest.digest());
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

	public static String encode(String... params) {
		List<String> list = new ArrayList<>(Arrays.asList(params));
		list.sort(String::compareTo);
		return encode(String.join("", list));
	}
}
